title: Difference between urethral circumference and artificial urinary sphincter cuff size, and its effect on postoperative incontinence.
abstract: OBJECTIVE
  We assessed whether a difference between intraoperative urethral circumference and artificial urinary sphincter cuff size affects postoperative outcomes.
  
  
  METHODS
  We evaluated the medical records of 87 males who underwent implantation of an artificial urinary sphincter between January 2006 and May 2010. A validated questionnaire was completed by 59 patients for long-term followup. The difference between urethral circumference and artificial urinary sphincter cuff size was calculated. Incontinence was recorded as daily pad use. The primary outcome variable was the postoperative decrease in incontinence. Multivariable linear regression was used to model the effect on postoperative incontinence of the difference between urethral circumference and cuff size.
  
  
  RESULTS
  Mean long-term followup was 4.2 years. Median preoperative incontinence was 8 pads per day and median abdominal leak point pressure was 50 cm H2O. Median urethral circumference was 38 mm and the median difference between urethral circumference and artificial urinary sphincter cuff size was 2.5 mm. Median postoperative incontinence was 1 pad per day. A 1 mm increase in the difference between urethral circumference and cuff size resulted in a 1.6% increase in incontinence by 4.5 months postoperatively (95% CI -3.1-6.2, p = 0.487). Paradoxically, each 1 mm increase improved postoperative continence at long-term followup by 29% (95% CI -15-56, p = 0.162).
  
  
  CONCLUSIONS
  At 4.5-month followup there was no statistical difference in pad use or patient satisfaction when the difference between urethral circumference and artificial urinary sphincter cuff size was less than 4 mm vs 4 mm or greater. However, at long-term followup the 4 mm or greater group reported statistically significantly better continence and satisfaction than the less than 4 mm group. This study does not support efforts to improve continence by minimizing cuff size but rather suggests that modestly up-sizing the cuff may produce improved long-term outcomes.
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee. Electronic address: jennifer.rothschild@vanderbilt.edu.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Rothschild
authors.affiliation: Department of Urological Surgery, Albany Medical College, Albany, New York.
authors.forename: Laura
authors.initials: L
authors.lastname: Chang Kit
authors.affiliation: Vanderbilt University School of Medicine, Nashville, Tennessee.
authors.forename: Lara
authors.initials: L
authors.lastname: Seltz
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Melissa
authors.initials: M
authors.lastname: Kaufman
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Roger
authors.initials: R
authors.lastname: Dmochowski
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Milam
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011184:Postoperative Period; D019919:Prosthesis Implantation; D016896:Treatment Outcome; D014521:Urethra / Q000473:pathology*; D014549:Urinary Incontinence / Q000473:pathology / Q000601:surgery*; D016741:Urinary Sphincter, Artificial
keywords: ALPP; AUS; BMI; RRP; TURP; XRT; abdominal leak point pressure; artificial; artificial urinary sphincter; body mass index; difference between implanted AUS cuff size and measured urethral circumference; external beam radiation therapy; male; outcome and process assessment (health care); radical retropubic prostatectomy; transurethral prostate resection; urethra; urinary incontinence; urinary sphincter; ΔC